Edit: Well, this shows that I'm not a doctor. I have no idea if Hepatitis C can kill as quickly as this. Maybe he was diagnosed very late and his malady already is at its final stage?
lol no! you lost something in translation...
Such sentence is very common in my (Belgian) entourage.
This is also why he adds he is smiling.
I would guess that it's metastatic cancer. Mentioning the liver is an indication. Once the liver's involved, cancer gets very hard to treat. Typical chemotherapy is killing the cancer by flooding the body with poison, and doing that when the liver's compromised is often fruitless (and painful).
Most likely, the doctors have stopped treatment, in which case 30 days is a reasonable median, but he'll be essentially functional until the last 2 weeks. However, there are cases (although they're quite rare) of people living for months or even years after that happens. Spontaneous remission is uncommon (less than 1%) but it does occur. That's yet another reason why doctors don't like giving specific timelines.